Gubernat, Maciej
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inżynieria materiałowa
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Item type:Article, Access status: Open Access , The impact of chemical functionalization of carbon nanotubes on the electrochemical performance of carbon fiber/pyrocarbon/carbon nanotube composites as potential materials for electrodes for nerve cell stimulation(2024) Zambrzycki, Marcel; Wielowski, Ryszard; Gubernat, Maciej; Jantas, Danuta; Paczosa-Bator, Beata; Frączek-Szczypta, Aneta
Wydział Inżynierii Materiałowej i CeramikiIn this work, we propose a new carbon–carbon (C–C) composites as a potential materials for electrodes for neural stimulation in neurodegenerative disorders. The C–C composites were made via chemical vapour deposition (CVD) synthesis of pyrocarbon on carbon fibers, with subsequent thermal spray deposition of carbon nanotubes (CNT). Different CNT types were tested to evaluate their impact on electrochemical and biological performance. Materials were analyzed for microstructure, surface chemistry, and electrochemical properties, then tested using SH-SY5Y neuroblastoma cells for biological assessment. The C–C composites coated with a hydroxy-terminated CNT demonstrated significantly enhanced electrochemical properties, in particular increased cathodal charge capacity up to 12.51 mC cm−2, a wide safe potential window of −1.53 to 1.26 V, and decreased impedance, and cut-off frequency (fcut-off = 0.16 kHz). No acute negative biological responses of the materials were detected after 48 h of exposition. Such properties significantly outperform the properties of platinum, which is the basic element of platinum electrodes, demonstrating the excellent performance of the obtained composites and showing it may constitute the basic element of carbon electrodes for nerve stimulation in the future. Our work presents the method for obtaining biologically inert carbon composite micro-electrodes which can potentially be adapted to neural stimulation.Item type:Article, Access status: Open Access , Exploring CVD Method for Synthesizing Carbon–Carbon Composites as Materials to Contact with Nerve Tissue(2023) Frączek-Szczypta, Aneta; Kondracka, Natalia; Zambrzycki, Marcel; Gubernat, Maciej; Czaja, Paweł; Pawlyta, Miroslawa; Jeleń, Piotr; Wielowski, Ryszard; Jantas, Danuta
Wydział Inżynierii Materiałowej i CeramikiThe main purpose of these studies was to obtain carbon–carbon composites with a core built of carbon fibers and a matrix in the form of pyrolytic carbon (PyC), obtained by using the chemical vapor deposition (CVD) method with direct electrical heating of a bundle of carbon fibers as a potential electrode material for nerve tissue stimulation. The methods used for the synthesis of PyC proposed in this paper allow us, with the appropriate selection of parameters, to obtain reproducible composites in the form of rods with diameters of about 300 µm in 120 s (CF_PyC_120). To evaluate the materials, various methods such as scanning electron microscopy (SEM), scanning transmission electron microscope (STEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and tensiometer techniques were used to study their microstructural, structural, chemical composition, surface morphology, and surface wettability. Assessing their applicability for contact with nervous tissue cells, the evaluation of cytotoxicity and biocompatibility using the SH-SY5Y human neurob lastoma cell line was performed. Viability and cytotoxicity tests (WST-1 and LDH release) along with cell morphology examination demonstrated that the CF_PyC_120 composites showed high biocompatibility compared to the reference sample (Pt wire), and the best adhesion of cells to the surface among all tested materials.Item type:Article, Access status: Open Access , Study on heat-treated pyrolytic carbon deposited from methane on directly heated carbon fibres(2024) Wielowski, Ryszard ; Czaja, Paweł ; Piekarczyk, Wojciech; Zambrzycki, Marcel; Gubernat, Maciej; Frączek-Szczypta, Aneta
Wydział Inżynierii Materiałowej i CeramikiThe study investigated the morphology, microstructure, structure, texture, and mechanical properties of heat-treated at 1600 °C and 2000 °C pyrolytic carbon (PyC) deposited from methane using various methods such as scanning electron microscopy (SEM), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), Raman spectroscopy, and ultrasonic dynamic measurements of Young's modulus. The PyC was synthesised at 1100 °C using a chemical vapour deposition (CVD) method with direct electrical heating of the two types of carbon fibres (CFs). The results showed that the PyC had a low- and medium-texture (LT and MT PyC). Analysis of the graphitization trajectory allowed the determination of structural changes in the material as a function of temperature, including the growth of crystallites and an increase in the crystallinity proportion without the significant rearrangement within PyC. The crystallite size and the number of interstitial defects has increased with temperature that controlled mechanical properties. Therefore, based on the results obtained, the most suitable composites for further research in the context of electrodes for stimulation of nervous tissue were obtained at the temperature of their synthesis, i.e. at 1100 °C.